It has long been recognized that the efficiency and performance of gas turbine engines could be improved by increasing the temperature of the gas through the turbine section. Historically, these temperatures have been limited by the materials, usually high temperature steel or nickel alloy, used to form the first stage stator vanes. To permit higher gas temperatures it has been proposed to form the first stage stator vanes from a high density, high strength, silicon nitride, or silicon carbide ceramic which can withstand higher temperatures than steels or nickel alloys. However, the use of ceramic stator vanes necessitates a ceramic-to-metal interface at which the difference in thermal expansion between the ceramic vane and the metallic support structure must be accommodated so that the vanes remain fixed relative to the structure despite temperature changes in the gas. It also necessitates that the ceramic-to-metal interface prevent the vanes from twisting when subjected to aerodynamic loads.
Thus, there is a need for a stator vane assembly in a gas turbine engine in which ceramic stator vanes are mounted to a metallic support structure in such a way so as accommodate the thermal mismatch between ceramic and metallic.